Portable boom



Aug. 4, 1959 J. H. HoLAN ET AL PORTABLE BOOM 2 Sheets-Sheet 1 Filed SeptA 25 1957 INVENToRs J'Ames HowARu HOLAN m HERMAN J. TocHE.

y :5a/1415, TM: 4 M9 26ML Arfonnsvs Aug. 4, 1959 J. H. HoLAN ET AL 2,897,979

PORTABLE BOOM Filed Sept. 23, 1957 2 Sheets-Sheet 2 n 'NVENToR. JAMES HOWARD HoLANm HERMAN J. TRocHa ATTORNEYS United States Patent PORTABLE BOOM James Howard Holan, Rocky River, and Herman J. Troche, Fairview Park, Ohio, assignors to J. H. Holan Corporation, Cleveland, Ohio, a corporation of Ohio Application September 23, 1957, Serial No. 685,661

9.Claims. (Cl. 212-8) This invention relates generally to portable booms of the type that may be collapsed and stowedl on a vehicle body when not in use and more particularly relates to an improved arrangement for positioning the boom throughout its operating range.

Portable booms are conventional equipment on many types of wheeled utility vehiclesV and are adapted to handle various types of loads. This invention is concerned primarily with the type of portable boom that is an integral part of the wheeled vehicle and may be collapsed on the vehicle body in self-Storing .position when not in use. This type of boom -ordinarily embodies an open A-frame having two side legs which are pivoted at their lower end to the vehicle body and which are arched at their upper ends towards an apex on which is mounted a sheave or the like for use in conjunction with a winch and cable in the conventional manner. Such a boom may be positioned from storage throughout its operating range by hydraulic or other suitable means coacting between the vehicle body and the boom frame.

It is a general object of this invention to provide an improved construction for a portable boom which will more eiectively handle various loads throughout its operating range and also mo-re efliciently permit its presentation to an operating condition from a` storage position on the vehicle body. t

Another object of this `invention relates to the provision of an improved arrangement for directly controlling the position of the portable boom from storage throughout its entire operating range. v

A further object of this invention relates to the provision of an improved arrangement for positioning the portable boom with increased leverage in the load lifting range.

Briefly, these and other objectives are obtained in accordance with this invention by providing an open A-frame type boom having a pair of fabricated rectangular section legs joined at their apex and having their free extremities pivotally mounted in suitable guides at the rear of the vehicle. Each leg of the frame isA pivotally connected near its apex to a fluid actuated piston which, in turn, is disposed in an operatingcylinder having its opposite extremity pivotally connected respectivelylto the corresponding guides adjacent the pivoted extremities of the A-frame legs so that the piston assembly is free to follow the movement of the frame.

In accordance with this invention, the connection between the cylinder and the guide is preferably a compound pivotal connection accomplished through an anchor lever arm assembly having a pivotal connection at one end to the cylinder and pivotal connection at the other end to the corresponding guide and carrying adjacent the pivotal connection to the guide a roller which is adapted to continuously engage a cam on the pivoted extremity of the corresponding frame leg. The cam coacts with the roller carried by the anchor lever arm assembly during initial movement from the storage position on the vehicle .body to an intermediate position to keep the anchor arm 2,897,979 Patented Aug. 4, 1959 'ice and the anchor arm assembly. The shifting is accom plished by means of an abutment on the anchor arm which is engaged by the corresponding guide in the intermediate position to lock the arm against further movement. As a result, the cylinder leverage is increased in the heavier load lifting range.

In the drawings:

Fig. 1 is a side elevation of a wheeled utility vehicle carrying the portable boom of this invention;

Fig. 2 is a rear elevation illustrating the portable boom in raised position;

Fig. 3 is a fragmentary side elevation of the boom positioning mechanism;

Fig. 4 is an edge view of an anchor lever arm assembly forming part of the boom positioning mechanism of this invention;

Fig. 5 is a side view of the anchor lever arm assembly of Figure 4; and

Fig. 6 is a sectional view takenralong the lines 6 6 in Fig. 2.

Referring now to the drawings and more particularly to Figures 1 and 2 thereof there is shown a wheeled utility vehicle 10 having a body indicated generally at 11 and carrying at lits rear end a portable boom in the form of an A frame having a pair of legs 12 and 14 which'converge at their upper extremities towards a common apex and which are pivotally mounted at their lower free extremities to pivot pins 15 and 16 mounted at the rear of ,the vehicle body. In the preferred form, best shownin Fig. 6, the legs 12 and 14 are constructed of fabricated rectangular metal sections to provide aV lightweight boom frame having uniform unit stress throughout. The boom is adapted to seat in self-storing position on top of the vehicle body, as shown in full lines, in Fig. 1, and yet is capable of being positioned in a vertical plane about its pivotal connections to the rear of the vehicle body to any one of an inlinite number of selected operating positions indicated in part by the dotted lines in Figure 1.

In the preferred form shown, the portable boom is positioned by means of extensible lluid actuated motors which have piston rods such as 20 pivotally connected at one end to brackets such as 22 on the corresponding legs 12 and 14 of the A-frame adjacent the apex. Each of the pistons is reciprocally disposed within corresponding cylinders such as 24 whose lower extremities are pivotally connected to corresponding anchor lever arm assemblies suchas 26 which in turn are pivotally connected at their opposite extremities respectively to the corresponding guides at the rear of the vehicle body as will be hereinafter more fully described. The legs 12 and 14 coact with the corresponding anchor lever arm assemblies 26 and 27 to apply one leverage during initial movement of the boom from storage to an intermediate position and thereafter automatically coact to provide an increased `leverage when the boom is positioned towards the heavier load-lifting portion of its operating range.

Referring now more particularly to Figures 2 through 5 of the drawings, it is seen that the leg supporting guides at the rear of the vehicle body are each formed by mounting upstanding plates 28 and 29 iny spaced parallel relation at the rear `of the body. Since both sides of the boom frame are identical in construction, the detailed description of that construction will hereinafter berconned to the side of the ame including the leg 12; it being under-i stood that this description will apply equally well to the other side of the frame. Thus, the lower extremity of the leg 12 carries a plate member 30 which is journaled for rotation on the spindle 15 that extends transversely through the guide plates Y28 and 29. The corresponding anchor lever arm assembly 26 is preferably constructed from a pair of similar plate-like side members 32 and 33 which are inter-connected at one end yby a rod 34 forming the pivot pin for the lower extremity of the cylinder 24 and at the other end by a rod 36 which forms the spindle for a roller 37. Another rod 38 interconnects the plates 32 and 33 intermediate their ends and forms the spindle upon which is rotatably journaled another roller 40. The extremity of the anchor lever arm assembly 26 which carries the roller 37 is disposed between the guide plates 28 and 29 and has aligned apertures 39 which are journaled on a pivot pin 41 extending transversely through the plates in spaced relation below the pivotal connection to the side leg 12.

With this arrangement, the extensible iiuid actuated motor consisting of the piston rod and cylinder 24 together with the anchor lever arm assembly 26 will follow the boom frame as it is rotated in a vertical plane. The operating leverage acting on the boom with this arrangement corresponds to the distance between the pivotal connections of the leg 12 and the anchor lever arm assembly 26 to the guide plates 28 and 29. Although this relatively short lever arm may be entirely adequate to position the boom from a storage position to an intermediate operating position corresponding, for example, to the dotted line position C, it may not be sufcient to eectively operate the boom throughout the remainder of its heavier loadlifting range. Therefore, in accordance with this invention, means are provided as will be hereinafter more fully described to extend the lever arm in the heavier load-lifting portion of its operating range.

To accomplish the foregoing, the plate member 30 is provided with an arcuate formation 42 for the purpose of presenting a cam surface for coaction with the roller 37 carried -by the adjacent extremity of the corresponding anchor lever arm assembly 26. The arcuate surface 42 is so designed that the roller extremity of the anchor lever arm assembly 26 maintains the anchor lever arm assembly and the operating piston and cylinder in close parallel proximity to the leg 12 until the entire assembly is positioned to the intermediate position C which corresponds to the point where the roller 37 passes the lobe of the cam surface 42. From that point on, as the piston rod 20 is further extended, the roller 37 is guided along arcuate portion 42 of the plate 30 so that the anchor lever arm o assembly 26 remains stationary. Inclined abutments 43 and 44 are provided on each side member 32 and 33 respectively. Thus, when the overall assembly attains the position C, these abutments engage the rear edges of the corresponding guide plates 28 and 29 and positively prevent further travel of the anchor lever arm assembly 26 in the directionof the boom movement. As a result, the piston and cylinder assembly, instead of following the boom frame about the pivotal connection of the anchor lever arm assembly to the guide plates 28 and 29, thereafter rotates about the axis of the rod 34 at the opposite end of the anchor lever arm assembly and provides an increased or extended leverage for the boom for the remainder or heavier load lifting portion of its operating range.

Since each of the extensible erecting motors is of the double-acting type, the pistons operate as compression members during the initial positioning of the boom from storage to the vertical position and, thereafter, for the remainder of the boom operation they act as tension members controlling movements of the boom throughout the remainder of its working range. The abutments 43 and 44 on the corresponding anchor lever arm assemblies prevent overrunning of the anchor arms in the extended operating or working range of the boom and, in the reverse operation, when the boom is returned from its working range to storage position on top the vehicle body, the operating pistons again reverse their operation from tension to compression members permitting direct control of movement of the boom throughout its entire operating range. Any conventional fluid system including a suitable pump and control valves, which may be operated from a power take-off on the transmission of the vehicle, can be applied to reciprocate the erecting motors.

Thus, there has been provided in accordance with this invention an improved construction for a portable boom which provides for more effective operation of the boom throughout its operating range and for a simpler and more eicient presentation and retraction ofthe boom to and from a self-storing position on top of the vehicle body. The construction includes an improved arrangement for positioning the 'boom which automatically provides an increased leverage in the heavier load-lifting portion of its operating range and a direct control of the boom throughout its entire operating range.

We have shown and described what we consider to be the preferred embodiments of our invention, and it will be obvious to those skilled in the art that other changes and modifications may be made without departing from the scope of our invention as defined in the appended claims.

We claim:

l. In a portable boom pivotably mounted at one end on a support for swinging movement about a horizontal axis from a storage position to a load supporting position and through a load supporting operating range, extensible erecting means for said boom attached at one end to the boom outwardly therealong with respect to the pivotal connection of the boom and said support to swing the boom and at the other end to said support, said extensible erecting means including an extensible arm and a link pivotally joined to each other at their extremities, said link pivotally connected at its other end to said support adjacent but in spaced relation to the pivotal axis of said boom, fulcrum retaining means co-acting with said link to retain the fulcrum of said extensible erecting means at the pivotal connection of said link in said support during the portion of the path of rotation of said boom from the storage position to the load supporting position, and fulcrum shifting means co-acting with said link to shift the fulcrum of said extensible erecting means from the pivotal connection of said link in said support to the pivotal connection joining said link and said extensible arm in their extremities during the load supporting operating range.

2. In the portable boom of claim l wherein the extensible erecting means includes a cylinder and fluid-actuated double-acting piston operably disposed thereon, means pivotally coupling the piston to the boom outwardly therealong with respect to the pivotal connection between the boom and the support and other means coupling the cylinder through a link to the support, and wherein said fulcrum retaining means coacts to restrain rotation ofthe cylinder and piston assembly about one pivotal axis of said link and wherein said fulcrum shifting means coacts to shift the axis of rotation of the cylinder and piston assembly to the other pivotal axis of said link, the latter pivotal axis being spaced a greater distance from the horizontal axis of rotation of the boom than the first pivotal axis to apply the increased leverage to the boom.

3. In the portable boom of claim 2 wherein additional means are provided for coaction between the link and the support to positively maintain the other pivotal axis of the link as the axis of rotation for the cylinder and piston assembly throughout the load supporting range of the boom.

4. In the portable boom of claim l wherein said link includes an anchor arm having one end pivotally connected to the cylinder and the other end pivotally connected to the support adjacent but in spaced relation fromv the pivot axis of the boom, and wherein said fulcrum retaining means includes a cam guide on the pivoted end of the boom and a cam follower on the adjacent end of the anchor arm coacting therewith to cause the anchor arm to follow the boom as it is swung from storage to the load supporting range.

5. In the portable boom of claim 1 wherein said link includes an anchor arm having one end pivotally connected to the cylinder and the other end pivotally connected to the support adjacent but in spaced relation from the pivot axis of the boom, and wherein said fulcrum shifting means includes a cam guide on the pivoted end of the boom and a cam follower on the adjacent end of the anchor arm coacting therewith after the rboomt has been positioned to the load supporting range to cause the anchor arm to remain fixed in the attained positioned, whereby the cylinder and piston assembly will thereafter rotate about the pivotal connection between the cylinder and the anchor arm and thereby apply an increased leverage to the boom throughout its load supporting range.

6. In a portable boom having one end pivotally mounted in a support for swinging movement from a storage position to a load supporting position and through a load supporting operating range the combination comprising, an extensible iuid motor and an anchor arm coacting between the boom and the support to swing the boom, said extensible iluid motor having one end pivotally connected to the boom outwardly therealong with respect to the pivotal connection between the boom and the support and having its other end pivotally connected to one end of the anchor arms, the other end of said anchor arm being pivotally connected to the support in spaced relation from the pivotal connection lbetween the lboorn and the support, means coacting between the boom and the anchor arm to cause initial rotation of the uid motor and anchor arm assembly about the pivotal connection between the anchor arm and the support, and other means coacting between-the boom and the anchor arm at an intermediate position in its path of travel to maintain the anchor arm iixed in its attained position and thereby cause further rotation of the extensible fluid motor to shift to an axis coincident with its pivotal connection to the anchor arm.

7. In a portable boom pivotally mounted at one end on a support for swinging movement about a horizontal axis between a storage position and a range of load supporting positions the combination comprising, linearly extensible erecting means having one end pivotally connected to the boom outwardly therealong with respect to the pivotal connection between the 'boom and the support, a link between the support and the other end of said erecting means including two pivot axes one of which is spaced further from the boom pivot axis than the other, means adapted for coaction therewith during rotation of the boom from storage to an initial load-supporting position to restrict rotation of said erecting means to the pivot axis, and other means adapted for coaction therewith during rotation of the boom throughout the remainder of the load supporting range to cause rotation of the erecting means on the pivot axis furthest ffrom the boom pivot axis.

8. The combination comprising a wheeled vehicle, a boom pivotably mounted at one end on a support for swinging movement about a horizontal axis from a storage position to a load supporting position and through a load supporting operating range, extensible erecting means for said boom attached at one end to the boom outwardly therealong with respect to the pivotal connection of the boom and said support to swing the boom and at the other end to said support, said extensible erecting means including an extensible arm and a link pivotally joined to each other at their extremities, said link pivotally connected at its other end to said support adjacent but in spaced relation to the pivotal axis of said boom, fulcrum retaining means coacting with said link to retain the fulcrum of said extensible erecting means at the pivotal connection of said link in said support during the portion of the path of rotation of said boom from the'storage position to the load supporting position, and fulcrum shifting means coacting with said link to shift the fulcrum of said extensible erecting means from the pivotal connection of said link in said support to the pivotal connection joining said link and said extensible arm in their extremities during the load supporting operating range.

9. The combination of claim 8 wherein said extensible erecting means includes a link attached to one end of said vehicle having two pivot axes, one of which is spaced farther from the boom pivot axis than the other, and wherein said fulcrum retaining means includes a cam guide adapted for coaction with said link to restrict rotation of said extensible means to the pivot axis closest to the boom and wherein said fulcrum shifting means include another cam guide adapted to transfer and maintain the axis of rotation of the extensible means coincident with the pivot axis farthest Ifrom the pivot axis from the boom.

References Cited in the tile of this patent UNITED STATES PATENTS 1,941,952 Nickles Ian. 2, 1934 2,649,210 Marchese Aug. 18, 1953 2,733,818 Gregersen Feb. 7, 1956 2,753,055 Hall July 3, 1956 2,786,580 Balogh Mar. 26, 1957 2,786,581 Balogh Mar. 26, 1957 

